diff mbox

[dpdk-dev,v2] metrics: fix potential missing NULL termination

Message ID 20180220160559.1143-1-remy.horton@intel.com (mailing list archive)
State Accepted, archived
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Remy Horton Feb. 20, 2018, 4:05 p.m. UTC 
  Fixes a potential memory overrun detected by Coverity.
This overrun cannot currently happen in practice because
rte_metrics_reg_names() explicitly forces the last name
character to be a NULL terminator. This patch adds the
same enforcement to rte_metrics_get_names() in order to
correct the warning, as well as using snprintf instead
of strncpy to copy name strings.

Coverity issue: 143434
Fixes: 349950ddb9c5 ("metrics: add information metrics library")
Fixes: 710cab6f675a ("metrics: fix out of bound access")

Signed-off-by: Remy Horton <remy.horton@intel.com>

--
Changes in v2
* Replace strncpy with snprintf
---
 lib/librte_metrics/rte_metrics.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

Comments

Ferruh Yigit March 22, 2018, 10:33 a.m. UTC | #1 
On 2/20/2018 4:05 PM, Remy Horton wrote:
> Fixes a potential memory overrun detected by Coverity.
> This overrun cannot currently happen in practice because
> rte_metrics_reg_names() explicitly forces the last name
> character to be a NULL terminator. This patch adds the
> same enforcement to rte_metrics_get_names() in order to
> correct the warning, as well as using snprintf instead
> of strncpy to copy name strings.

There is a patch from Bruce to convert snprintf to strlcpy [1], this patch can
be part of that one.

[1]
https://dpdk.org/dev/patchwork/patch/35976/

> 
> Coverity issue: 143434
> Fixes: 349950ddb9c5 ("metrics: add information metrics library")
> Fixes: 710cab6f675a ("metrics: fix out of bound access")
> 
> Signed-off-by: Remy Horton <remy.horton@intel.com>

<...>
Thomas Monjalon April 4, 2018, 2:09 p.m. UTC | #2 
22/03/2018 11:33, Ferruh Yigit:
> On 2/20/2018 4:05 PM, Remy Horton wrote:
> > Fixes a potential memory overrun detected by Coverity.
> > This overrun cannot currently happen in practice because
> > rte_metrics_reg_names() explicitly forces the last name
> > character to be a NULL terminator. This patch adds the
> > same enforcement to rte_metrics_get_names() in order to
> > correct the warning, as well as using snprintf instead
> > of strncpy to copy name strings.
> 
> There is a patch from Bruce to convert snprintf to strlcpy [1], this patch can
> be part of that one.
> 
> [1]
> https://dpdk.org/dev/patchwork/patch/35976/
> 
> > 
> > Coverity issue: 143434
> > Fixes: 349950ddb9c5 ("metrics: add information metrics library")
> > Fixes: 710cab6f675a ("metrics: fix out of bound access")
> > 
> > Signed-off-by: Remy Horton <remy.horton@intel.com>

Updated to use strlcpy and applied.
diff mbox

Patch

diff --git a/lib/librte_metrics/rte_metrics.c b/lib/librte_metrics/rte_metrics.c
index 556ae1b..b0f5450 100644
--- a/lib/librte_metrics/rte_metrics.c
+++ b/lib/librte_metrics/rte_metrics.c
@@ -113,10 +113,8 @@  rte_metrics_reg_names(const char * const *names, uint16_t cnt_names)
 
 	for (idx_name = 0; idx_name < cnt_names; idx_name++) {
 		entry = &stats->metadata[idx_name + stats->cnt_stats];
-		strncpy(entry->name, names[idx_name],
-			RTE_METRICS_MAX_NAME_LEN);
-		/* Enforce NULL-termination */
-		entry->name[RTE_METRICS_MAX_NAME_LEN - 1] = '\0';
+		snprintf(entry->name, RTE_METRICS_MAX_NAME_LEN,
+			"%s", names[idx_name]);
 		memset(entry->value, 0, sizeof(entry->value));
 		entry->idx_next_stat = idx_name + stats->cnt_stats + 1;
 	}
@@ -215,9 +213,9 @@  rte_metrics_get_names(struct rte_metric_name *names,
 			return return_value;
 		}
 		for (idx_name = 0; idx_name < stats->cnt_stats; idx_name++)
-			strncpy(names[idx_name].name,
-				stats->metadata[idx_name].name,
-				RTE_METRICS_MAX_NAME_LEN);
+			snprintf(names[idx_name].name,
+				RTE_METRICS_MAX_NAME_LEN,
+				"%s", stats->metadata[idx_name].name);
 	}
 	return_value = stats->cnt_stats;
 	rte_spinlock_unlock(&stats->lock);